1. Field of the Invention
This invention relates to a process for the production of alkane polyols from epoxidized fatty acids and/or fatty acid esters.
2. Statement of Related Art
Long-chain polyols are produced from natural unsaturated fatty acids or esters thereof which are converted with potassium permanganate, percarboxylic acid or other suitable reagents into the polyhydroxy fatty acids or esters thereof. This is followed by reduction with lithium alanate or sodium to the polyol (B. Palameta, M. Prostenik, Tetrahedron 19 (10) (1963) 1463; F. J. Julietti et al., Soc. 1960 (11) 4514).
When percarboxylic acids are used to hydroxylate the double bonds, epoxides are initially formed. The epoxides are converted into the corresponding ester alcohols in the presence of carboxylic acids with ring opening. According to the prior art, the ester alcohols are hydrolyzed to the polyhydroxy-carboxylic acids and reduced with lithium alanate. The reduction is preferably preceded by esterification with a short-chain alcohol.
When the reaction is carried out with ricinoleic acid as starting material, a tetrol is obtained as the end product (R. Subbarao, K. T. Achaya, J. Sci. Ind. Res. (India) 19B (1960) 482-84).
Epoxy fatty acids also have been reduced directly to diols with lithium alanate (F. J. Julietti et al., Chem. Ind. 27 (1960) 874). However, a potential alcohol group is lost in this reaction.
Unfortunately, the prior processes do not provide an efficient and economical way of providing high quality alkane polyol products having a maximum number of alcohol groups. Therefore, an object of the present invention is to provide a process for the production of alkanetriols and alkane polyols from mono- and/or poly-epoxidized fatty acids and/or fatty acid esters, in which the maximum number of possible alcohol groups per molecule is formed; and in which hydrolysis steps are unnecessary.